The present disclosure relates, in general, to electronics and, more particularly, to operational amplifiers (e.g., high voltage precision amplifiers) and level shifters for shifting reference levels of signals for driving input transfer gates.
Precision operational amplifiers may be used to perform signal conditioning (e.g., for analog sensors). In this regard, the amplifiers may perform low voltage amplification and/or bandpass filtering. Additionally, precision operational amplifiers may be used to perform high- or low-side current sensing (e.g., for power management). In this regard, the amplifiers may be included as part of a feedback loop.
In an ideal operational amplifier, a differential input signal is amplified such that the output is 0V when the input signal is 0V. However, in actual devices, an output of 0 volts may result from a non-zero differential input signal that compensates internal voltage or current offsets (mismatches). The non-zero differential input is referred to as the input offset voltage. Architectures used for reducing the input offset voltage include using a chopper amplifier architecture, an auto-zero architecture or different combinations of chopper amplifier and auto-zero architectures.